A liquid ring machine is described in German Patent Application No. 195 169 94. In operating this machine with hard, i.e., limestone-containing, water, for example, limestone deposits are formed in the inner housing. In this case, the thickness of the limestone deposit increases depending on the temperature. A particularly critical stage is reached when, for example, the axial clearances between the rotor and the inner housing are filled with limestone. In operating the machine, in particular, in the case of longer shutdowns, the rotor may become jammed due to this limestone deposit or it may be axially displaced by hitting the limestone layer. This displacement of the rotor may also result in the rotor being eroded on the opposite side by the housing. Material failure or motor damage may result. The same may occur in the event of thickening corrosion layers.
So far, there have been no specific and effective measures against these phenomena for liquid ring machines. Chemical additives in the water or ionic accelerators may reduce limestone levels in this special case by chemically binding the limestone contained in the water or reducing calcium ions in the water added. In addition to being ecologically questionable, the cost of these measures is very high and they are also ill-suited to combat corrosion problems, for example.